[FFmpeg-devel,3/4] h2645_parse: Make ff_h2645_packet_split reference-compatible

diff --git a/libavcodec/cbs_h2645.c b/libavcodec/cbs_h2645.c
index 6846cad0bb..df2b5f3f5e 100644
--- a/libavcodec/cbs_h2645.c
+++ b/libavcodec/cbs_h2645.c
@@ -611,7 +611,7 @@  static int cbs_h2645_split_fragment(CodedBitstreamContext *ctx,
 
         err = ff_h2645_packet_split(&priv->read_packet,
                                     frag->data + start, end - start,
-                                    ctx->log_ctx, 1, 2, AV_CODEC_ID_H264, 1);
+                                    ctx->log_ctx, 1, 2, AV_CODEC_ID_H264, 1, NULL);
         if (err < 0) {
             av_log(ctx->log_ctx, AV_LOG_ERROR, "Failed to split AVCC SPS array.\n");
             return err;
@@ -635,7 +635,7 @@  static int cbs_h2645_split_fragment(CodedBitstreamContext *ctx,
 
         err = ff_h2645_packet_split(&priv->read_packet,
                                     frag->data + start, end - start,
-                                    ctx->log_ctx, 1, 2, AV_CODEC_ID_H264, 1);
+                                    ctx->log_ctx, 1, 2, AV_CODEC_ID_H264, 1, NULL);
         if (err < 0) {
             av_log(ctx->log_ctx, AV_LOG_ERROR, "Failed to split AVCC PPS array.\n");
             return err;
@@ -689,7 +689,7 @@  static int cbs_h2645_split_fragment(CodedBitstreamContext *ctx,
 
             err = ff_h2645_packet_split(&priv->read_packet,
                                         frag->data + start, end - start,
-                                        ctx->log_ctx, 1, 2, AV_CODEC_ID_HEVC, 1);
+                                        ctx->log_ctx, 1, 2, AV_CODEC_ID_HEVC, 1, NULL);
             if (err < 0) {
                 av_log(ctx->log_ctx, AV_LOG_ERROR, "Failed to split "
                        "HVCC array %d (%d NAL units of type %d).\n",
@@ -708,7 +708,7 @@  static int cbs_h2645_split_fragment(CodedBitstreamContext *ctx,
                                     frag->data, frag->data_size,
                                     ctx->log_ctx,
                                     priv->mp4, priv->nal_length_size,
-                                    codec_id, 1);
+                                    codec_id, 1, NULL);
         if (err < 0)
             return err;
 
@@ -1510,7 +1510,7 @@  static void cbs_h264_close(CodedBitstreamContext *ctx)
     CodedBitstreamH264Context *h264 = ctx->priv_data;
     int i;
 
-    ff_h2645_packet_uninit(&h264->common.read_packet);
+    ff_h2645_packet_uninit(&h264->common.read_packet, NULL);
 
     av_freep(&h264->common.write_buffer);
 
@@ -1525,7 +1525,7 @@  static void cbs_h265_close(CodedBitstreamContext *ctx)
     CodedBitstreamH265Context *h265 = ctx->priv_data;
     int i;
 
-    ff_h2645_packet_uninit(&h265->common.read_packet);
+    ff_h2645_packet_uninit(&h265->common.read_packet, NULL);
 
     av_freep(&h265->common.write_buffer);
 
diff --git a/libavcodec/extract_extradata_bsf.c b/libavcodec/extract_extradata_bsf.c
index f37427c7e1..5598064eb3 100644
--- a/libavcodec/extract_extradata_bsf.c
+++ b/libavcodec/extract_extradata_bsf.c
@@ -157,7 +157,7 @@  static int extract_extradata_h2645(AVBSFContext *ctx, AVPacket *pkt,
     }
 
     ret = ff_h2645_packet_split(&s->h2645_pkt, pkt->data, pkt->size,
-                                ctx, 0, 0, ctx->par_in->codec_id, 1);
+                                ctx, 0, 0, ctx->par_in->codec_id, 1, NULL);
     if (ret < 0)
         return ret;
 
@@ -393,7 +393,7 @@  static void extract_extradata_close(AVBSFContext *ctx)
 {
     ExtractExtradataContext *s = ctx->priv_data;
     ff_av1_packet_uninit(&s->av1_pkt);
-    ff_h2645_packet_uninit(&s->h2645_pkt);
+    ff_h2645_packet_uninit(&s->h2645_pkt, NULL);
 }
 
 static const enum AVCodecID codec_ids[] = {
diff --git a/libavcodec/h2645_parse.c b/libavcodec/h2645_parse.c
index aaa4b8f443..b1ae39d8ef 100644
--- a/libavcodec/h2645_parse.c
+++ b/libavcodec/h2645_parse.c
@@ -345,7 +345,7 @@  static int find_next_start_code(const uint8_t *buf, const uint8_t *next_avc)
 
 int ff_h2645_packet_split(H2645Packet *pkt, const uint8_t *buf, int length,
                           void *logctx, int is_nalff, int nal_length_size,
-                          enum AVCodecID codec_id, int small_padding)
+                          enum AVCodecID codec_id, int small_padding, AVBufferRef **ref)
 {
     GetByteContext bc;
     int consumed, ret = 0;
@@ -353,9 +353,22 @@  int ff_h2645_packet_split(H2645Packet *pkt, const uint8_t *buf, int length,
     int64_t padding = small_padding ? 0 : MAX_MBPAIR_SIZE;
 
     bytestream2_init(&bc, buf, length);
-    av_fast_padded_malloc(&pkt->rbsp.rbsp_buffer, &pkt->rbsp.rbsp_buffer_alloc_size, length + padding);
-    if (!pkt->rbsp.rbsp_buffer)
-        return AVERROR(ENOMEM);
+    if (!ref) {
+        av_fast_padded_malloc(&pkt->rbsp.rbsp_buffer, &pkt->rbsp.rbsp_buffer_alloc_size, length + padding);
+        if (!pkt->rbsp.rbsp_buffer)
+            return AVERROR(ENOMEM);
+    } else {
+        int err;
+        err = avpriv_buffer_fast_alloc(ref, length + padding + AV_INPUT_BUFFER_PADDING_SIZE);
+        if (err < 0) {
+            pkt->rbsp.rbsp_buffer            = NULL;
+            pkt->rbsp.rbsp_buffer_alloc_size = 0;
+            return err;
+        }
+
+        pkt->rbsp.rbsp_buffer            = (*ref)->data;
+        pkt->rbsp.rbsp_buffer_alloc_size = (*ref)->size;
+    }
 
     pkt->rbsp.rbsp_buffer_size = 0;
     pkt->nb_nals = 0;
@@ -466,7 +479,7 @@  int ff_h2645_packet_split(H2645Packet *pkt, const uint8_t *buf, int length,
     return 0;
 }
 
-void ff_h2645_packet_uninit(H2645Packet *pkt)
+void ff_h2645_packet_uninit(H2645Packet *pkt, AVBufferRef *ref)
 {
     int i;
     for (i = 0; i < pkt->nals_allocated; i++) {
@@ -474,6 +487,9 @@  void ff_h2645_packet_uninit(H2645Packet *pkt)
     }
     av_freep(&pkt->nals);
     pkt->nals_allocated = 0;
-    av_freep(&pkt->rbsp.rbsp_buffer);
+    if (!ref)
+        av_freep(&pkt->rbsp.rbsp_buffer);
+    else
+        pkt->rbsp.rbsp_buffer = NULL;
     pkt->rbsp.rbsp_buffer_alloc_size = pkt->rbsp.rbsp_buffer_size = 0;
 }
diff --git a/libavcodec/h2645_parse.h b/libavcodec/h2645_parse.h
index a0a5ca5868..6afabf2d62 100644
--- a/libavcodec/h2645_parse.h
+++ b/libavcodec/h2645_parse.h
@@ -23,6 +23,7 @@ 
 
 #include <stdint.h>
 
+#include "libavutil/buffer.h"
 #include "avcodec.h"
 #include "get_bits.h"
 
@@ -91,15 +92,19 @@  int ff_h2645_extract_rbsp(const uint8_t *src, int length, H2645RBSP *rbsp,
  * the data is contained in the input buffer pointed to by buf.
  * Otherwise, the unescaped data is part of the rbsp_buffer described by the
  * packet's H2645RBSP.
+ * If ref is not NULL, *ref must either be NULL in which case pkt's underlying
+ * rbsp_buffer must be NULL, too, or (*ref)->buffer owns rbsp_buffer. In both
+ * cases, rbsp_buffer will be owned by **ref afterwards.
  */
 int ff_h2645_packet_split(H2645Packet *pkt, const uint8_t *buf, int length,
                           void *logctx, int is_nalff, int nal_length_size,
-                          enum AVCodecID codec_id, int small_padding);
+                          enum AVCodecID codec_id, int small_padding, AVBufferRef **ref);
 
 /**
  * Free all the allocated memory in the packet.
+ * If ref is supplied, the underlying AVBuffer is supposed to own the rbsp_buffer.
  */
-void ff_h2645_packet_uninit(H2645Packet *pkt);
+void ff_h2645_packet_uninit(H2645Packet *pkt, AVBufferRef *ref);
 
 static inline int get_nalsize(int nal_length_size, const uint8_t *buf,
                               int buf_size, int *buf_index, void *logctx)
diff --git a/libavcodec/h264_parse.c b/libavcodec/h264_parse.c
index 34ffe3b1fe..57f0e8692e 100644
--- a/libavcodec/h264_parse.c
+++ b/libavcodec/h264_parse.c
@@ -359,7 +359,7 @@  static int decode_extradata_ps(const uint8_t *data, int size, H264ParamSets *ps,
     H2645Packet pkt = { 0 };
     int i, ret = 0;
 
-    ret = ff_h2645_packet_split(&pkt, data, size, logctx, is_avc, 2, AV_CODEC_ID_H264, 1);
+    ret = ff_h2645_packet_split(&pkt, data, size, logctx, is_avc, 2, AV_CODEC_ID_H264, 1, NULL);
     if (ret < 0) {
         ret = 0;
         goto fail;
@@ -387,7 +387,7 @@  static int decode_extradata_ps(const uint8_t *data, int size, H264ParamSets *ps,
     }
 
 fail:
-    ff_h2645_packet_uninit(&pkt);
+    ff_h2645_packet_uninit(&pkt, NULL);
     return ret;
 }
 
diff --git a/libavcodec/h264dec.c b/libavcodec/h264dec.c
index 00d922fbe9..62a25eda31 100644
--- a/libavcodec/h264dec.c
+++ b/libavcodec/h264dec.c
@@ -377,7 +377,7 @@  static av_cold int h264_decode_end(AVCodecContext *avctx)
     ff_h264_sei_uninit(&h->sei);
     ff_h264_ps_uninit(&h->ps);
 
-    ff_h2645_packet_uninit(&h->pkt);
+    ff_h2645_packet_uninit(&h->pkt, NULL);
 
     ff_h264_unref_picture(h, &h->cur_pic);
     av_frame_free(&h->cur_pic.f);
@@ -622,8 +622,8 @@  static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size)
             h->is_avc = 1;
     }
 
-    ret = ff_h2645_packet_split(&h->pkt, buf, buf_size, avctx, h->is_avc,
-                                h->nal_length_size, avctx->codec_id, avctx->flags2 & AV_CODEC_FLAG2_FAST);
+    ret = ff_h2645_packet_split(&h->pkt, buf, buf_size, avctx, h->is_avc, h->nal_length_size,
+                                avctx->codec_id, avctx->flags2 & AV_CODEC_FLAG2_FAST, NULL);
     if (ret < 0) {
         av_log(avctx, AV_LOG_ERROR,
                "Error splitting the input into NAL units.\n");
diff --git a/libavcodec/hevc_parse.c b/libavcodec/hevc_parse.c
index b1b27eef09..3cf9e3757e 100644
--- a/libavcodec/hevc_parse.c
+++ b/libavcodec/hevc_parse.c
@@ -29,7 +29,8 @@  static int hevc_decode_nal_units(const uint8_t *buf, int buf_size, HEVCParamSets
     int ret = 0;
     H2645Packet pkt = { 0 };
 
-    ret = ff_h2645_packet_split(&pkt, buf, buf_size, logctx, is_nalff, nal_length_size, AV_CODEC_ID_HEVC, 1);
+    ret = ff_h2645_packet_split(&pkt, buf, buf_size, logctx, is_nalff,
+                                nal_length_size, AV_CODEC_ID_HEVC, 1, NULL);
     if (ret < 0) {
         goto done;
     }
@@ -67,7 +68,7 @@  static int hevc_decode_nal_units(const uint8_t *buf, int buf_size, HEVCParamSets
     }
 
 done:
-    ff_h2645_packet_uninit(&pkt);
+    ff_h2645_packet_uninit(&pkt, NULL);
     if (err_recognition & AV_EF_EXPLODE)
         return ret;
 
diff --git a/libavcodec/hevc_parser.c b/libavcodec/hevc_parser.c
index 369d1338d0..51c240069d 100644
--- a/libavcodec/hevc_parser.c
+++ b/libavcodec/hevc_parser.c
@@ -194,7 +194,7 @@  static int parse_nal_units(AVCodecParserContext *s, const uint8_t *buf,
     ff_hevc_reset_sei(sei);
 
     ret = ff_h2645_packet_split(&ctx->pkt, buf, buf_size, avctx, ctx->is_avc,
-                                ctx->nal_length_size, AV_CODEC_ID_HEVC, 1);
+                                ctx->nal_length_size, AV_CODEC_ID_HEVC, 1, NULL);
     if (ret < 0)
         return ret;
 
@@ -363,7 +363,7 @@  static void hevc_parser_close(AVCodecParserContext *s)
     HEVCParserContext *ctx = s->priv_data;
 
     ff_hevc_ps_uninit(&ctx->ps);
-    ff_h2645_packet_uninit(&ctx->pkt);
+    ff_h2645_packet_uninit(&ctx->pkt, NULL);
     ff_hevc_reset_sei(&ctx->sei);
 
     av_freep(&ctx->pc.buffer);
diff --git a/libavcodec/hevcdec.c b/libavcodec/hevcdec.c
index a3b5c8cb71..42fdb090ec 100644
--- a/libavcodec/hevcdec.c
+++ b/libavcodec/hevcdec.c
@@ -3024,7 +3024,7 @@  static int decode_nal_units(HEVCContext *s, const uint8_t *buf, int length)
     /* split the input packet into NAL units, so we know the upper bound on the
      * number of slices in the frame */
     ret = ff_h2645_packet_split(&s->pkt, buf, length, s->avctx, s->is_nalff,
-                                s->nal_length_size, s->avctx->codec_id, 1);
+                                s->nal_length_size, s->avctx->codec_id, 1, NULL);
     if (ret < 0) {
         av_log(s->avctx, AV_LOG_ERROR,
                "Error splitting the input into NAL units.\n");
@@ -3305,7 +3305,7 @@  static av_cold int hevc_decode_free(AVCodecContext *avctx)
         s->HEVClc = NULL;
     av_freep(&s->HEVClcList[0]);
 
-    ff_h2645_packet_uninit(&s->pkt);
+    ff_h2645_packet_uninit(&s->pkt, NULL);
 
     return 0;
 }